There are certainly a lot of useless majors. But that doesn't imply all of them are useless.
"the fact that educational debt in America can never be voided through bankruptcy seems like a conscious systemic decision to create debt slaves."
I'm not in the US, but isn't the rationale for that construct to make people more credit worthy? Ultimately you have to convince somebody to give a random person a lot of money on the odd chance that they'll finish their education and earn the money back. I suppose if you don't like "educational debt", you could also try to convince somebody to give you another type of loan.